Done Old and heavy used 500D but some pretty nice lenses in my collection.Now the 5D3 is pretty nice!

esbenlp wrote:

I wouldn't personally need the extra megapixels for crops as I don't have the need for the extra reach that cropping can give.

I would really like the extra "cropping reach" but the 1.6x cropping from 22.3MP still gives some acceptable 8.7MP resolution. And of course I'm going to keep the 500D for better reach in "good light".

Dual Chips heat faster and hotter than single chips - the advantage of the heat is speed.

Single Chips dont heat up as much as dual.

It would be interesting to see since the 7D uses dual DigicIV and the 5D3 uses a single DigicV - and in my esperience the only thing that gets hot is my hand clinging onto the camera, trying to keep it steady during video.

the Weather sealing on the 7D is a step above the 5D2, and Im sure the Mk3 is better than the 7D. I think it might work out to be a balanced compromise between heat, speed and processing power when it comes to video. Especially at 60FPS.

Also keep in mind, 1080p is capped at that resolution - the entire sensor isnt working all the pixels to shoot video.

Perhaps, and Im just thinking half full here, there is a way to vent with a one way valve? lol.... well, my 7D has once fillmed for 4 hours, basically filming as soon as the camera allows me to once the limit is reached and cools, resets and clears the buffer etc. Doesnt heat up and its the second best sealing compared to the 1DX at the time. Maybe we are getting a little overzealous with the nay-saying.

I dont think the world will end if the mark 4 gets a bit warm, let alone if it does at all, I think we all have reserved the position that its already going to, and we havent seen this happen in the 7D or the 1Dx as of yet, let along the D800 or other similar.

I've never used them for filming but I have used long exposure continuous shooting for hours on end. It never gave an overheat warning. Then again I guess video is more actively driving the sensor than a long exposure would.

@popo, I think the heat doesnt come from the sensor - its a receiving and sending technology - Its the processor that generates the heat. Its the one that is sending several billions of electrical impulses per microsecond. And electricity generates heat and without heat sinks, well - the processors are like computer cores, theres a dedicated fan attached to them.

If Canon had technology that could work at "several billions of electrical impulses per microsecond" off a battery then every computing device as we know it would be obsolete!

Electricity is converted to heat whenever it passes through resistance. This usually happens when it does some work. It can be at the sensor or the processor, and without measuring it we don't know how it is split. Processing cores can run hot safely. The only reason typical computer processors usually have a heatsink and fan is because they are capable of emitting many 10s or 100s of watts of heat that needs to be shifted to keep them within their comfort zone. The battery in the 7D/5D2 is about 13Wh so you're not going to run into high power outputs. Simple conduction is adequate to keep most of it in a comfortable thermal operating region.

just to go slightly off topic, there is no way you could cool a camera body with a airflow from a few vent holes. To do that effectively you would need a fan and imagine how much dust and stuff you would end up blowing in there

Put your hand on some aluminum or metal, it will feel cold as the heat is conducted away straight away. Yet its the same temperature as the wood or other material that is less conductive, if they are in the same room/same environment.

I would suggest that the magnesium body would make an excellent heatsink.

If you were to go for an airflow system, no one says the airflow needs to go to dust sensitive areas. Think along the lines of a heat exchanger. If there is space, maybe even heatpipes could be used to transfer heat from one location to another, but this is overkill until you go for more extreme heat outputs beyond that likely to be reached in a consumer grade camera.

Like #2: Auto-ISO now supposedly works in Manual. So I can now quickly adjust my creative preferences for shutter & aperture each shot, and get a decent exposure w/out having to ALSO fiddle with multiple buttons/ dials/ readouts/ etc. to get a workable ISO. This will be a bonus feature for event photography, at least in my usage when exposure is constantly changing widely. (With post-processing options, ISO/grain is not a realtime creative choice. I just want a decent exposure and cleanest possible file, and will add any grain effects afterwards, if I want them at all.)

Dislike #2: The 5d2 should have had this. Oh, you can set ISO to Auto in Manual on the 5d2, but it doesn't actually work. I believe (having an extensive realtime programming background) that this should be a relatively minor firmware mod. I'm convinced there's no good technical reason the 5d2 doesn't do this. There's a marketing reason, of course, but that's misguided in my opinion. Canon could and should provide this capability in the 5d2 with a minor firmware upgrade.

Like #3: In the 5d3 Av mode, a minimum shutter speed can be set.

Dislike #3: As with Auto-ISO, it is ridiculous that the 5d2 cannot do this. Canon could and should provide this capability in the 5d2 with a minor firmware upgrade.

Like #4: Improved AF.

Dislike #4: Probably nothing to dislike here. I find AF on the 5d2 fair to middlin'. Can't say having 61 focus points will do a thing for me, though. Just make the center one work fast and accurately, and I'd be more than happy. How about they keep the other 60 and drop my price by $1K?

Like #5: DOF Preview button on the right, where it belongs.

Dislike #5: They long ago removed the aperture rings from all the lenses. So putting the DOF Preview button back in the correct spot accomplishes little. With aperture rings on the lenses, you could do all of (1) hold up the camera - even with a big lens, (2) adjust focus, zoom, and aperture back & forth, and (3) turn DOF Preview off & on, to quickly zero in on just the effect you want. But w/out aperture rings on the lenses, you can only do two out of the above three operations handheld. You really need all three. It's kind of frustrating that manual control has gone backwards from the system that worked so much better, decades ago. If you never used that system, you probably don't miss it. But if you did, you know what I'm talking about.

If Canon had technology that could work at "several billions of electrical impulses per microsecond" off a battery then every computing device as we know it would be obsolete!

Perhaps my Hyperbole didnt come through as nutty enough... Yes, I know, I was trying to exaggerate. But processors do get hot as they process. I just dont think its such a big thing. If it was, then Canon is a generation behind Nikon in processing technology, and that doesnt sound right